New HPC-Scratch Space

General usage instructions

Since the current scratch space of the cluster LEO1 is approaching its capacity limit a new consolidated scratch space is available under /hpc-scratch. It is currently shared by the two cluster systems, LEO1 and LCC. In the near future other HPC scratch systems are likely to be consolidated as well.

The consolidated scratch space became a new ZID service which is a prerequisite for both services LEO1 and LCC. Users with an account on either of the two systems are automatically provided with this HPC-SCRATCH service. The category of your HPC-SCRATCH account has been selected according to the amount of file space used up to now. You may, however, contact us to adapt the file system size to your specific demands.

In the following we provide some recommendations on how to access the common scratch directory from different HPC systems:

Your HPC scratch directory includes a sub directory for both HPC systems, LEO1 and LCC.
Usage example for user cXXXYYY:
```
[cXXXYYY@login.leo1 ~]$ ls /hpc-scratch/cXXX/
lcc       leo1
```
HPC systems might differ with respect to architecture and instruction set. Both clusters, the AMD based LEO1 and the Intel based LCC, rely on the x86_64 instruction set. However, if you are using highly optimized code with, e.g., SSE instructions you might want to use different scratch spaces for different executables. In this case you can use the environment variable HPC_SCRATCH pointing to the cluster specific directory within your common scratch directory.
Issuing the command "echo $HPC_SCRATCH" on LEO1 gives:
```
[cXXXYYY@login.leo1 ~]$ echo $HPC_SCRATCH
/hpc-scratch/cXXXYYY/leo1
```
Issuing the same command on LCC shows:
```
[cXXXYYY@lcc16-be1t3 ~]$ echo $HPC_SCRATCH
/hpc-scratch/cXXXYYY/lcc
```
Each user's scratch file system is managed by the automounter.
This means: If you have not used your scratch space recently and issue "ls /hpc-scratch" or the like, the listing will not contain your directory (or may even appear empty). Just "cd /hpc-scratch/$USER" or use any other method to access a file or directory in "/hpc-scratch/$USER". Your scratch directory will be automatically mounted and visible, so you do not need to modify any jobs that access data in /hpc-scratch/$USER.
As before, by design and policy, there are no backups of scratch. Users are responsible for safeguarding their data according to their needs.

Specific usage instructions

We ask you to perform the following actions for each HPC system you have access to. In exceptional cases the given deadlines may be postponed by a maximum of one or two weeks.

Running jobs can still use the old scratch directories for reading and writing until they are finished.

HC-CLUSTER users (login via hc-ma.uibk.ac.at)

Please refer to the HC-CLUSTER migration announcement and mind the following time table:

Deadlines	Status	Action
Sept. 24th to Oct. 19th	The old scratch directory /scratch-hc/<username> is mounted in read/write mode.	Please migrate your application(s) to the LEO1 cluster and move your data from /scratch-hc/<username> to /hpc-scratch/<username>/leo1.
Oct 20th to Nov 6th	The old scratch directory /scratch-hc/<username> is mounted in read-only mode.	Please move your data from /scratch-hc/<username> to /hpc-scratch/<username>/leo1.
After Nov 7th	Your old scratch directory /scratch-hc/<username> is no longer available. The migration from the HC-CLUSTER to the LEO1 cluster should be finished by then.

LEO1 users (login via login.leo1.uibk.ac.at)

Your scratch directory is called /hpc-scratch/<username>.
We advice you to use the HPC_SCRATCH environment variable in order to access your cluster specific scratch directory /hpc-scratch/<username>/leo1.

Deadlines	Status	Action
Sept. 24th to Nov. 6th	Your old scratch directory /scratch-hc/<username> is mounted in read-only mode! It is accessible through the master node login.leo1.uibk.ac.at.	Please move your data from /scratch-hc/<username> to /hpc-scratch/<username>/leo1.
After Nov 7th	Your old scratch directory /scratch-hc/<username> is no longer available.

LCC users (login via lcc.uibk.ac.at)

Deadlines	Status	Action
Sept. 24th to Nov. 6th	The old scratch directory /scratch/<username> is mounted in read-only mode. It is accessible through the login node lcc.uibk.ac.at alias zid-cc.uibk.ac.at.	Please move your data from /scratch/<username> to the new scratch directory /hpc-scratch/<username>/lcc.
After Nov 7th	Your old scratch directory /scratch/<username> is no longer available.